Do you need planning permission for a conservatory?
The size limits that let a conservatory go up without planning permission in England, when the building regulations exemption applies and how it is lost, and the rules in Wales, Scotland and NI.
A conservatory in England usually needs no planning permission. It counts as a single-storey extension, so it is permitted development if it goes no more than 3 metres beyond the original rear wall, or 4 metres on a detached house, and is no more than 4 metres high. We set out every limit, the homes that lose these rights, when building regulations apply, and what changes in Wales, Scotland and Northern Ireland.
Do you need planning permission for a conservatory?
In England a conservatory falls under the same planning rules as any other extension. That makes it permitted development as long as it fits the size and position limits below and the house still has its permitted development rights.
A conservatory that breaks any one of the limits, or sits on a home without those rights, needs planning permission. For a house that means a householder application, which costs £548 in England from 1 April 2026.
How big can a conservatory be without planning permission?
A conservatory has to meet every one of the permitted development size limits for a single-storey extension. They are measured from the original house: the house as it stood on 1 July 1948, or as it was first built if it is newer.
| Rule | Limit |
|---|---|
| Rear, semi-detached or terraced house | 3 m beyond the original rear wall |
| Rear, detached house | 4 m beyond the original rear wall |
| Rear, with prior approval | 6 m, or 8 m on a detached house |
| Height | No more than 4 m, and no higher than the highest part of the roof |
| Eaves | No higher than the house's eaves; no more than 3 m within 2 m of a boundary |
| Side conservatory | Single storey, no more than 4 m high, no wider than half the original house; a wraparound meets the rear limits too |
| Front of the house | Not beyond the principal elevation, or a side wall facing a road |
| Land covered | Extensions and outbuildings on no more than half the land around the original house |
| Materials | The similar-materials condition does not apply to conservatories |
Rear conservatories
Depth runs from the base of the original rear wall to the outside face of the conservatory's end wall, not to the gutter. A 3.5 metre deep conservatory on a semi-detached house is past the 3 metre limit and needs prior approval or a planning application. On a detached house the same conservatory is permitted development.
On a bungalow the eaves rule does most of the work. The conservatory's eaves can sit no higher than the bungalow's own, which keeps its side walls low whatever the depth.
Larger rear conservatories through prior approval
Outside conservation areas and other designated land, a rear conservatory can go to 6 metres, or 8 metres on a detached house. You notify the council and pay £249, the council tells the adjoining neighbours and lets them object, and work can start once it grants approval, says approval is not needed, or 42 days pass without a decision.
If the house already has an extension
Earlier extensions count against the depth, whether they were built under permitted development or with planning permission. A 3 metre conservatory on the back of a 2 metre kitchen extension on a semi sits 5 metres from the original rear wall, so it needs prior approval.
When a conservatory needs planning permission
A conservatory needs a planning application, or at least a check with the council first, in these cases:
- Over the limits. It breaks any limit in the table, including one on the front of the house.
- A flat or maisonette. There are no householder permitted development rights to use.
- A converted house. A home created from a shop, farm building or other commercial building under permitted development cannot use the rights.
- Rights removed. An Article 4 direction, or a condition on the house's planning permission, removes the rights, particularly on newer housing developments.
- Designated land. In a conservation area, National Park, National Landscape, the Broads or a World Heritage Site, a side conservatory needs permission and the prior approval route is closed. A single-storey rear one within 3 or 4 metres still needs none.
- A listed building. Listed building consent may be needed on top of any planning question.
Conservatories next to a boundary or a neighbour's wall
On a semi-detached or terraced house the conservatory often runs along the boundary. Within 2 metres of it the eaves can be no more than 3 metres high, and the 3 metre depth limit holds unless the council grants prior approval for more.
In England and Wales you must also tell the neighbours before building on or near a party wall or boundary, and a party wall agreement is a separate step from anything the council decides. Two more checks sit outside planning: a restrictive covenant in the title deeds can limit what you build, and building over a drain or sewer can need a build-over agreement with the water company.
Do conservatories need building regulations approval?
A conservatory in England is exempt from building regulations approval when it meets all of these conditions:
- It is single storey and built at ground level.
- Its floor area is less than 30 square metres.
- It is separated from the house by external-quality walls, doors or windows.
- Any heating is independent of the house's system, with its own temperature and on/off controls.
- Its glazing and any fixed electrics meet the building regulations requirements that apply to them.
The exemption is written for a mostly glazed room, with at least 50% of its new walls and 75% of its roof glazed. The building regulations exemption does not cover a room with more solid wall or roof than that, which needs approval like any other extension.
When the exemption is lost
The exemption lasts only as long as the conditions do. Any new structural opening between the conservatory and the house needs approval, even when the conservatory itself is exempt. Taking out the doors between the two, running the main heating in without separate controls, or making the room 30 square metres or more turns it into an extension in building regulations terms.
Solid roofs and orangeries
For planning, replacing a conservatory roof like for like usually needs no permission, but a new solid roof that raises the height can. For building regulations, a mostly solid roof takes the room below the 75% glazed roof mark, so it needs approval as an extension.
Whether you build an orangery or a conservatory, the planning limits are the same, because both are single-storey extensions. The roof is what separates them for building control, and an orangery's solid roof usually falls short of the glazing the exemption needs.
Conservatory planning fees and lawful development certificates
Nobody approves a conservatory that is permitted development, so there is no fee. A lawful development certificate from the council confirms in writing that it is lawful, and it is the proof a buyer's solicitor asks for when you sell. A conservatory that needs a householder application instead is typically decided within 8 weeks.
The 4-year rule and conservatories built without permission
The 4-year rule is the time limit after which a council can no longer take planning enforcement action against building work done without permission. It still applies in Wales. In England the limit became 10 years from substantial completion on 25 April 2024, with transitional rules for work finished before then.
Building regulations run separately: work done without approval can only be approved afterwards through regularisation from the council, for work carried out after 11 November 1985.
Conservatory rules in Wales, Scotland and Northern Ireland
Everything above is the England system. A conservatory in Cardiff, Edinburgh or Belfast is judged against its own nation's planning and building rules.
| Nation | Main planning limits without an application | Building regulations or warrant exemption |
|---|---|---|
| England | 3 m, or 4 m detached; 6 m or 8 m with prior approval; max 4 m high | Single storey, ground level, under 30 m², separated from the house, independent heating |
| Wales | Max 4 m long and 4 m high; no higher than the house's eaves | Separate Welsh building regulations |
| Scotland | Within 1 m of a boundary: 3 m on a terrace, 4 m on other houses; max 4 m high, eaves 3 m | Up to 8 m², at least 1 m from a boundary, no flue, appliance or sanitary facility |
| Northern Ireland | Rear: 4 m on a detached house, 3 m on others | Ground level, up to 30 m², heating not extended into it, no fixed combustion appliance |
Wales has run its own planning system since 2016. Under the Welsh Government's conservatory rules, a side conservatory can be no wider than half the house, and on designated land it can project only 3 metres and must be set back at least 1 metre from the front. There are no permitted development rights for a conservatory within the grounds of a listed building, or for flats.
Scotland's single-storey extension limits apply to an attached conservatory, with no permitted development rights in a conservation area or for flats. Under Schedule 1 of the Building (Scotland) Regulations 2004, an attached conservatory needs no building warrant only if it is 8 square metres or less, at least 1 metre from a boundary, has no flue, combustion appliance or sanitary facility, and its glazing meets the standard in the regulations.
In Northern Ireland, work at a listed building, in a conservation area or in an area of outstanding natural beauty needs a planning application. Schedule 2 of the Building Regulations (Northern Ireland) 2012 exempts a ground-level conservatory of up to 30 square metres if the heating is not extended into it, it has no fixed combustion appliance, and its glazing meets Part V.
Common questions
What size can a conservatory be without planning permission?
In England a rear conservatory can go 3 metres beyond the original rear wall of a semi-detached or terraced house, or 4 metres on a detached one, and be up to 4 metres high. A side conservatory can be no wider than half the house. Prior approval raises the rear limit to 6 or 8 metres.
What is the 4-year rule for conservatories?
The 4-year rule is the time limit after which a council can no longer take enforcement action against building work done without planning permission. It still applies in Wales. In England the limit for building work became 10 years from substantial completion on 25 April 2024.
Do you need planning permission for a conservatory with a solid roof?
A conservatory with a solid roof needs no planning permission in England if it fits the same size limits as any other single-storey extension. A replacement roof that raises the height can need permission. A mostly solid roof does take the conservatory out of the building regulations exemption.
Do I need planning permission for a conservatory if I already have an extension?
An existing extension counts against the permitted development depth, so the extension and the conservatory together must stay within 3 metres of the original rear wall, or 4 metres on a detached house. Prior approval covers a total of up to 6 or 8 metres.
Do you need planning permission for an orangery?
An orangery follows the same planning rules as a conservatory in England, because both are single-storey extensions. Its solid roof usually means it needs building regulations approval, where a mostly glazed conservatory can be exempt.
Do you need planning permission for a conservatory in Scotland?
A conservatory in Scotland can go up without planning permission within the Scottish single-storey extension limits, but not in a conservation area or on a flat. A building warrant is needed unless it is 8 square metres or less and at least 1 metre from a boundary.